What is svchost.exe And Why Is It Running? :: the How-To Geek

导读：
　　You are no doubt reading this article because you are wondering why on earth there are nearly a dozen processes running with the name svchost.exe. You can't kill them, and you don't remember starting them… so what are they?
　　So What Is It?
　　According to Microsoft: "svchost.exe is a generic host process name for services that run from dynamic-link libraries". Could we have that in english please?
　　Some time ago, Microsoft started moving all of the functionality from internal Windows services into .dll files instead of .exe files. From a programming perspective this makes more sense for reusability… but the problem is that you can't launch a .dll file directly from Windows, it has to be loaded up from a running executable (.exe). Thus the svchost.exe process was born.
　　Why Are There So Many svchost.exes Running?
　　If you've ever taken a look at the Services section in control panel you might notice that there are a Lot of services required by Windows. If every single service ran under a single svchost.exe instance, a failure in one might bring down all of Windows… so they are separated out.
　　Those services are organized into logical groups, and then a single svchost.exe instance is created for each group. For instance, one svchost.exe instance runs the 3 services related to the firewall. Another svchost.exe instance might run all the services related to the user interface, and so on.
　　So What Can I Do About It?
　　You can trim down unneeded services by disabling or stopping the services that don't absolutely need to be running. Additionally, if you are noticing very heavy CPU usage on a single svchost.exe instance you can restart the services running under that instance.
　　The biggest problem is identifying what services are being run on a particular svchost.exe instance… we'll cover that below.
　　If you are curious what we're talking about, just open up Task Manager and check the "Show processes from all users" box:
　　


　　
　　Checking From the Command Line (Vista or XP)
　　If you want to see what services are being hosted by a particular svchost.exe instance, you can use the tasklist command from the command prompt in order to see the list of services.
　　tasklist /SVC
　　


　　
　　The problem with using the command line method is that you don't necessarily know what these cryptic names refer to.
　　Checking in Task Manager in Vista
　　You can right-click on a particular svchost.exe process, and then choose the "Go to Service" option.
　　


　　
　　This will flip over to the Services tab, where the services running under that svchost.exe process will be selected:
　　


　　
　　The great thing about doing it this way is that you can see the real name under the Description column, so you can choose to disable the service if you don't want it running.
　　Using Process Explorer in Vista or XP
　　You can use the excellent Process Explorerutility from Microsoft/Sysinternals to see what services are running as a part of a svchost.exe process.
　　Hovering your mouse over one of the processes will show you a popup list of all the services:
　　


　　
　　Or you can double-click on a svchost.exe instance and select the Services tab, where you can choose to stop one of the services if you choose.
　　


　　
　　Disabling Services
　　Open up Services from the administrative tools section of Control Panel, or type services.mscinto the start menu search or run box.
　　Find the service in the list that you'd like to disable, and either double-click on it or right-click and choose Properties.
　　


　　
　　Change the Startup Type to Disabled, and then click the Stop button to immediately stop it.
　　
　　


　　
　　You could also use the command prompt to disable the service if you choose. In this command "trkwks" is the Service name from the above dialog, but if you go back to the tasklist command at the beginning of this article you'll notice you can find it there as well.
　　sc config trkwks start= disabled
　　Hopefully this helps somebody!
　　The Geek is the founder of How-To Geek and a geek enthusiast. When he's not coming up with great how-to articles, he's probably writing at his personal blog. This article was written on 01/24/08 and tagged with: Windows Vista, System Administration
　　Comments (68) Rich
　　I always wondered what this was and why so many were running. Thanks very much for the clear and excellent explanation!
　　Jon
　　Thanks for this! Like Rich said above, I've always wondered too!
　　Is there anywhere to get a list of the "common" windows processes that shouldn't be shut off; ie core windows services? That would help with making sure the mistakes are kept to a small minimum…
　　Much thanks!
　　The Geek
　　Jon,
　　I'm working on building a guide to all the windows services, but I'm not done yet. (lots of work involved).
　　In the meantime, you should check out Black Viper's guide, which is really top notch: http://www.blackviper.com/WinVista/servicecfg.htm 　　You should note that there's no "perfect" configuration for everybody… depending on what applications you are running you may or may not need a certain service.
　　Jon
　　Thanks again for the quick response! I totally agree with you with the "one config to bind them all" scenario never happening {no matter how much some might want it!
　　


　　}
　　I will check the Black Viper guide when I get home tonight!
　　Cheers,
　　Jon
　　whs
　　This is very useful and helpful. Thank you Geek for taking the time to put it together. WHS
　　Chris
　　Thanks for this excellent guide, it is hands down the best explanation of these svchost.exe processes I've read anywhere (I don't know why everyone always feels the need to be so cryptic about everything). Clear, concise, perfect. Thanks!
　　Jennifer
　　Thank you for this simple explanation. I work with .dll and .exe programs daily but am new to the field. This not only cleared things up for windows but explains why the programs I create need a .dll file to run.
　　k.s.reddy
　　Excellent information on svchost.exe. This simple, clear explanation clears all my doubts regarding svchost.exe. Thank u very much.
　　diya
　　What command are we supposed to enter in win2k?
　　tasklist /svc gives an message "'tasklist' is not recognized as an internal or external command,
　　operable program or batch file.".
　　Planet Lowyat
　　Thanks for the tips. I'm wondering what is this before.
　　Peter
　　Thank you so much for this awesome guide. Really very useful.
　　I would like to add one thing! If the service name is "scvhost.exe" then its a virus. Also if Username of "svchost.exe" service entry is other than "System", "Local Service" and "Network Service", then its a virus.
　　I found a good guide to know which Windows services are useless and can be stop:
　　I'll wait for your service guide.
　　Jimmy
　　THanks for the info! It's really nice! I wondering how to do it in Windows XP. I can't ge the "go to services" menu on right click, can you guide it on XP ?
　　Lawk Salih
　　Thanks for the post. I have stopped most of the unwanted services for the time being.
　　Best,
　　Lawk Salih
　　Mathieu
　　You answered the question I was tired of asking around and eventually forgot about it. If I have any more question about computers, i'll know where to come first next time.
　　Thanks!
　　Walter
　　Thanks.
　　All the info contained in this article was konown to me, it is the combination you propose that is valueable!
　　ScottK
　　Great article Jon! I've always wondered what all those svchost.exe's were.
　　Cartman
　　Excellent, Thanks for explaining this!
　　fedmich
　　Great article very easy to understand
　　John Powell
　　Thank you for the great explanation of something I have always wondered about.
　　Wes Sabi
　　tasklist is not included with XP home, only XP Pro
　　Pavan
　　And how do I go ahead doing this for non vista and non XP systems?
　　Chandoo
　　Thanks alot for this info, I have always wondered what svc processes are up to. @peter, thanks for the links…
　　joshua
　　This only works in Pro, you should indicate that. Most people that need this article will be running Home so its pretty irrelevant. Nice try though
　　abhishek bhatnagar
　　quite good post…but i think disabling services related to svchost.exe could prove a loss in some functionality…but its ok if someone knows about the service completely before disabling.
　　Peter
　　@chandoo
　　Welcome. This site and AskVG.com both are my favorite sites. Both are full of information and must visit sites. Thanks to both guys who spend their time to write such great tutorials for us.
　　Braintrove.com
　　Great article. Thanks!
　　Rene Zuleta
　　Ahhhhh thanks for this complete and easy to understand explanation.
　　I guess I can have some sleep finally!
　　Kyro_Kun
　　Thank you very much for the explanation.
　　Finally a good night sleep for us all!
　　dar
　　Kudos
　　-You've given a better explanation than searching on google a week could!
　　lankapo
　　gosh, thanks for the info. At last , I know what is svchost all about.
　　I always tweak my services sometime even crash my laptop.
　　what would be the must turn off service for vista?
　　Ryan
　　Thank you for this!
　　Ammar
　　Very informative. Thank you for all that you do.
　　ryanturner.com
　　Great article. I use another free program to do this on windows. It allows me to do service profiles…so I can switch from my developer profile to my gamer profile. Instantly clearing up resources. Even gives a graphical view of the services and their memory footprint.
　　It amazing the kinds of crappy services you find on your system. Ipod service.. wth I don't even have an ipod. Google Toolbar service - runs even when IE isnt open. Adobe Updater… the thing doesnt update until you open one of their apps anyway. I could go on… just check out the program. Its wicked.
　　Service Studio
　　www.mindswarm.com
　　Thanks to Dan for telling me about it.
　　aakash
　　Wow!, It's a great article. This site rocks man! I was always wondering what is this service all about but never actully try to dig it more.
　　Thanks for sharing.
　　Dimitarc and
　　I have answer to that…..its called LINUX and it has penguin on the cover.
　　Teen
　　tasklist /SVC | more
　　show all list
　　Pradeep
　　Great article
　　coolsak
　　awesome.
　　dave
　　What happens if you just have a regular home edition of XP.. I tried doing the cmd prompt with Tasklist/svc but it didn't work.
　　Darrell
　　To Dave: tasklist /svc works only with XP pro…….
　　gerald
　　Hi good evening..
　　I need Help.. theres a problem in my PC when I restart my computer I doesn’t restart..or it wont execute when I click “restart” and I just restart it manually……some of my friends told me its because of the Virus called “svchost.exe” does it possible…..can this be true….plssss Help me…
　　Steven Klassen
　　Great article, thanks!
　　Nikhil
　　Thanks a lot for the information.
　　Chris Dorn
　　why would I always have multiple msexe.exe running in my Task Manager on my XP home edition? Whenever I want to install a new program or uninstall a program I get an error message that another install is in progress. I have to shut off all instances of the msexe.exe then quickly hit the run (install) before they start baack up..What is up with that? I had AVG. now switched to NortonAV and I have a Spyware detector and Registry cleaner and I still have the same problem. Any advice?
　　Thank You!
　　Chris
　　Awesome explaination on the svchost.exe
　　techdudes
　　very nice info bro. This is the real thing newbies should know.
　　very detailed.
　　keep it up. i m blogging it.
　　Parth.
　　Pete
　　Thanks, well explained info.
　　fran
　　thank you for wour always excellent info, from Spain.
　　I sugest one topic: how it works, and how to reduce the amount of memory that consumes "iexplore.exe" ( in my case 56.956 K)
　　Thanks again
　　lester
　　hi
　　i am wondering if there is a guide on how to settle this problem for pc running on XP? thanks
　　Mary
　　This was exactly what I was looking for. Thanks.
　　Gouse
　　Good stuff……
　　jen
　　Thanks for the info! The only problem that I had (I'm not totally computer illiterate but I'm not a programmer), and this sounds stupid, but when you check the "show processes for all users box", what do you do then? I clicked the box and then nothing happened, the box was just checked. Sorry if this is a dumb question.
　　Pavan Patidar
　　Hey Guys really gr8 info about SVCHOST.EXE.
　　Peter thanks for the link provided..
　　tv
　　great job. Thanks a lot for the usefull and well-arranged informations.
　　Jordan
　　Fantastic INFO! Thank you!
　　Ravi Thapliyal
　　Great Article Jon!!! You really made all of us to tacit "svchost.exe” in a very proficient mode.
　　Dennis
　　I have XP Home and tasklist /svc gives a message "'tasklist' is not recognized as an internal or external command,
　　operable program or batch file.".
　　Audi
　　I had a few of svchost.exe running under user "SYSTEM". But then i had 2 svchost.exe running under my user name which is audi, i knew this was something else because its under my user name and not under the system's and in additional i was trying to find the source of web blocking program whiched blocked me from entering some web sites such as youtube.com, it even blocked me off from using firefox and not to mention disabling the function to see hidden files.. So i searched for svchost.exe using the search tool in the "start", and i find its location here: C:/Documents and Settings/Audi/Local Settings/Temp/MicrosoftPowerPoint.
　　it mention something like "autohotkey" and its icon is a "H" letter in a green box.
　　This confirms me that its some kinda bug. I've erased it completely, but it still shows up everytime i turn on my pc, tryied tracing it again and showed no results. Its useless trying to use anti-spyware/addware or even an anti virus. Its a bug in disguise under the name of svchost.exe to prevent detection. So how can i get this program/thing off my pc for good? any idea people? tq.
　　jordy la forge
　　I don't have any svchosts running, I think its stopping my "windows update" from working.
　　Tannis
　　Amazing! I have 13 svchost programs running at the moment. I know that some viruses pretend to be svchost, but I didn't know how to check what each of the svchost programs were doing. You have helped me a lot. Thanks!
　　kensonic
　　Another great tool for examining what is happening under Windows is What's Running?. It's free and available here: http://www.whatsrunning.net 　　JUSTIN
　　thanks to whoever wrote this article… it helped me gain a lot of info bout svchost…. i thought it was a virus…
　　Deyaa Addeen Fahmy
　　How can I thank you ?
　　God bless you.
　　Andrew Seaton
　　Great, well written article - Thanks!
　　ty chan
　　the explanation is so critically important. Millions of thanks!
　　French Rose in Italy
　　svchost essential for Windows. Had the 100% CPU problem after having unintentionally left my firewall off. Fixed the whole problem by 1) activating Firewall, running full virus scan 2) cleaning out all unecessary files, 3) download Windows Service Pack 2, KB 884020, Windows Security update for XP KB941644, and Windows Defender, 4) ran a scan with Windows Defender, 5) wiping hard drive with Ace Utilities (other programs do this), 6) Dowloaded CCleaner from CCleaner.com (free software), 7) and then defrag. CPU is normal. Tip turn off realtime for Windows Defender and run scan once a week
　　KO
　　Thanks to you and now thanks to HP. That's some good geeking!
　　KO
　　Adi
　　Great article. Thanks!
　　Eddie
　　So thats what it is!!! Sweet!! Thanks for the info!!
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